Acute complete heart block in dogs

A study has been conducted immediately and up to 18 days after the surgical production of complete heart block in dogs. Immediately after surgery cardiac output, coronary flow, and mean arterial pressure were reduced in rough proportion to the degree of bradycardia. In time, these measures began to return toward preoperative levels. Paralleling the diminished left ventricular work was a diminished left ventricular oxygen consumption with little consequent change in myocardial efficiency. Small rises were detected in central venous pressure. At autopsy, the only unequivocal abnormality was myocardial hypertrophy which became measurable between 2 and 18 days after operation

Plastic Deformation in Laser-Induced Shock Compression of Monocrystalline Copper

Copper monocrystals were subjected to shock compression at pressures of 10–60 GPa by a short (3 ns initial) duration laser pulse. Transmission electron microscopy revealed features consistent with previous observations of shock-compressed copper, albeit at pulse durations in the µs regime. The results suggest that the defect structure is generated at the shock front. A mechanism for dislocation generation is presented, providing a realistic prediction of dislocation density as a function of pressure. The threshold stress for deformation twinning in shock compression is calculated from the constitutive equations for slip, twinning, and the Swegle-Grady relationship

Inhibitory Deficits, Delay Aversion and Preschool AD/HD: Implications for the Dual Pathway Model

The dual pathway model proposes the existence of separate and neurobiologically distinct cognitive (inhibitory and more general executive dysfunction) and motivational (delay aversion) developmental routes to AD/HD. The study reported in this paper explores the relation between inhibitory deficits and delay aversion and their association with AD/HD in a group of three-year-old children. Children identified as having a pre-school equivalent of AD/HD (N=19) and controls (N=19), matched for gender and IQ, completed a battery of inhibition and delay tasks. Correlational and factor analysis supported a dissociation between inhibitory deficits (go-no-go, set shifting) and delay aversion (choice delay) with delay of gratification cross-loading. Children with AD/HD displayed more inhibitory deficits and were more delay averse than controls. The data support the value of the distinction between motivational and cognitive pathways to AD/HD. Furthermore, the data suggest that such a distinction is apparent relatively early on during development

Autistic young people’s experiences of transitioning to adulthood following the Children and Families Act 2014

Changes to special educational needs and disability (SEND) legislation in England were implemented in 2014. Here, we evaluate the impact of these changes from the perspective of 80 autistic young people aged 16–25 years. Using an online survey and/or interviews, we examined young people’s views on three key principles of the SEND reforms: the help and support provided to them; whether they were given a say in the choices and support that they were offered; and their satisfaction with their educational journeys and outcomes. The results paint a mixed picture. Our sample of young people reported varied experiences regarding the help and support they received, and how much of a say they had regarding the choices and support available to them. The types of schooling they accessed played a role here: young people in mainstream schools highlighted particular challenges in accessing appropriate support, while many young people in special schools said they felt well supported. Parental advocacy was crucial for all young people, as was having key ‘champions’ in the form of teachers who really knew them well. The need for the development of general life and self-advocacy skills was apparent, however, especially in preparing the young people for life after school. Encouragingly, most of our participants were generally happy with their current situation, despite identifying several areas for further improvement. Overall, the results highlight the importance of listening to—and learning from—autistic young people, throughout their educational journeys and especially as they transition to adulthood

Striatal dopamine D2 receptor binding of risperidone in schizophrenic patients as assessed by 123I-iodobenzamide SPECT: a comparative study with olanzapine

The aim of this investigation was to compare the degree of striatal dopamine-(D2) receptor blockade by two atypical antipsychotic drugs, risperidone and olanzapine. The percentage of D2 receptor occupancy during treatment was calculated by comparing the results of 123I-iodobenzamide SPECT with those from healthy control subjects. Twenty inpatients suffering from schizophrenia or schizoaffective psychosis according to DSM IV/ICD-10 criteria were treated with clinically recommended doses of risperidone and compared with 13 inpatients treated with up to 20 mg olanzapine. Neuroleptic dose and D2 receptor blockade correlated strongly for both risperidone (Pearson r = –0.86, p = 0.0001) and olanzapine (Pearson r = –0.77, p = 0.002). There was no significant difference between the D2 receptor occupancy of the two substances when given in the clinically recommended dose range (unpaired t-test, t= –0.112, p=0.911)

The transition to adulthood for autistic young people with additional learning needs: the views and experiences of education professionals in special schools

Education professionals (n = 41) in special schools were interviewed about supporting their autistic pupils transitioning to adulthood following the introduction of the Children and Families Act 2014. Our participants explained how they lacked the time to fully implement knowledge gained from training, leading to growing reliance on experiential expertise. While our participants reported employing a variety of methods to elicit the voices of pupils, they were uncertain how effective and ethical these were. Further, a lack of available opportunities meant that participants felt they could not always support young people in achieving their goals. Based on these findings, we recommend greater investment in the implementation of staff training, more flexibility for schools to be able to meaningfully elicit and act on pupils' voices, and better vocational opportunities for autistic young people with additional learning needs. This would enable the principles of the Act, which have been widely lauded, to become a closer reality

Transient x-ray diffraction used to diagnose shock compressed Si crystals on the Nova laser

Transient x-ray diffraction is used to record time-resolved information about the shock compression of materials. This technique has been applied on Nova shock experiments driven using a hohlraum x-ray drive. Data were recorded from the shock release at the free surface of a Si crystal, as well as from Si at an embedded ablator/Si interface. Modeling has been done to simulate the diffraction data incorporating the strained crystal rocking curves and Bragg diffraction efficiencies. Examples of the data and post-processed simulations are presented

X-ray Astronomy in the Laboratory with a Miniature Compact Object Produced by Laser-Driven Implosion

Laboratory spectroscopy of non-thermal equilibrium plasmas photoionized by intense radiation is a key to understanding compact objects, such as black holes, based on astronomical observations. This paper describes an experiment to study photoionizing plasmas in laboratory under well-defined and genuine conditions. Photoionized plasma is here generated using a 0.5-keV Planckian x-ray source created by means of a laser-driven implosion. The measured x-ray spectrum from the photoionized silicon plasma resembles those observed from the binary stars Cygnus X-3 and Vela X-1 with the Chandra x-ray satellite. This demonstrates that an extreme radiation field was produced in the laboratory, however, the theoretical interpretation of the laboratory spectrum significantly contradicts the generally accepted explanations in x-ray astronomy. This model experiment offers a novel test bed for validation and verification of computational codes used in x-ray astronomy.Comment: 5 pages, 4 figures are included. This is the original submitted version of the manuscript to be published in Nature Physic